What’s your function? Remember that song from “Schoolhouse Rock” back in the Dark Ages? If you can’t remember the words, I’ll tell you what a conjunction’s function is: It joins. It creates a junction when words, or sentences, or clauses, or phrases meet.
The most common conjunctions are AND and BUT. In addition, you can use OR or NOR, YET, or SO. These are all the garden variety, but some other day I’ll torture you with coordinating, subordinating, and correlative conjunctions.
I’m willing to bet that an English teacher once told you never to begin a sentence with a conjunction. I’ll also bet you were never given a reason for that “rule”— because there isn’t one. You can start a sentence with any word in the English language. And if anyone challenges you, blame me.